Conventionally, as one method of carrying out data communication between electronic devices, a method called human body communication in which data communication is carried out by using a human body as a transmission route has been proposed. For example, one disclosed in JP-A-2001-77735 is known. According to this, a technique is disclosed in which human body communication is carried out stably by bringing two electrodes into contact with a human body or by electrostatically coupling them and by measuring and controlling the amount of electric current flowing across the electrodes.
In addition, JP-A-2002-152145 discloses a human body communication technique is disclosed which makes use of a change in the refractive index when an electro-optical crystal connected to a transceiver antenna is electromagnetically coupled to a transmitted electric field.
As a technique making use of such a human body communication technique, one disclosed in JP-A-2001-144661 is known. According to the technique disclosed therein, it is stated that as a human body communication function is mounted on a wearable device, authentication processing can be carried out with respect to a service providing terminal by communication via a human body.
Alternatively, in a technique disclosed in JP-A-2003-190302, it is stated that a human body communication function is mounted on a remote controller and a health appliance such as a massage chair, and if the user operates the remote controller in a state of being seated in the massage chair, a control signal is transmitted to the massage chair through the human body, so that a cord based on wired communication is not required, and wireless communication need not be carried out, facilitating the ease of use and making it possible to attain reduction in cost.